The negative tone of the Massachusetts Senate race is taking its toll on the images of both Republican U.S. Sen. Scott Brown and Democratic Harvard Law School Professor Elizabeth Warren, according to a new poll conducted by The MassINC Polling Group.

The poll found that between July and October, Brown’s unfavorable rating rose from 30 percent to 39 percent, while Warren’s unfavorable rating rose from 24 percent to 38 percent. The candidates are now essentially tied in favorable/unfavorable ratings, which stand at 47/39 for Brown and 48/38 for Warren.

During that time, the Senate race has turned increasingly negative, with both candidates attacking one another in campaign appearances and in advertising. Outside groups have also gotten involved, sending out negative mailers.

As in past polls, Democratic President Barack Obama remains popular in Massachusetts – with favorable/unfavorable ratings of 64/34. Republican presidential nominee Mitt Romney, the former Massachusetts governor, remains unpopular with favorable/unfavorable ratings of 36/59.

The biggest change from July is in a growing sense of consumer confidence among Massachusetts residents, a measurement that includes several factors and that rose to its highest levels since the poll started measuring it in January 2011. The poll found that consumer confidence is increasing along party lines, with Warren supporters feeling significantly more optimistic about the economy than Brown supporters.

The poll of 500 Massachusetts residents was conducted Oct. 17-20 and has a margin of error of 4.4 percent.